diff --git a/src/lib/isIBAN.js b/src/lib/isIBAN.js
index b4ceebe46..dad485a62 100644
--- a/src/lib/isIBAN.js
+++ b/src/lib/isIBAN.js
@@ -11,13 +11,13 @@ const ibanRegexThroughCountryCode = {
   AE: /^(AE[0-9]{2})\d{3}\d{16}$/,
   AL: /^(AL[0-9]{2})\d{8}[A-Z0-9]{16}$/,
   AT: /^(AT[0-9]{2})\d{16}$/,
-  AZ: /^(AZ[0-9]{2})[A-Z0-9]{4}\d{20}$/,
+  AZ: /^(AZ[0-9]{2})[A-Z]{4}[A-Z0-9]{20}$/,
   BA: /^(BA[0-9]{2})\d{16}$/,
   BE: /^(BE[0-9]{2})\d{12}$/,
   BG: /^(BG[0-9]{2})[A-Z]{4}\d{6}[A-Z0-9]{8}$/,
   BH: /^(BH[0-9]{2})[A-Z]{4}[A-Z0-9]{14}$/,
   BR: /^(BR[0-9]{2})\d{23}[A-Z]{1}[A-Z0-9]{1}$/,
-  BY: /^(BY[0-9]{2})[A-Z0-9]{4}\d{20}$/,
+  BY: /^(BY[0-9]{2})[A-Z0-9]{4}\d{4}[A-Z0-9]{16}$/,
   CH: /^(CH[0-9]{2})\d{5}[A-Z0-9]{12}$/,
   CR: /^(CR[0-9]{2})\d{18}$/,
   CY: /^(CY[0-9]{2})\d{8}[A-Z0-9]{16}$/,
@@ -46,7 +46,7 @@ const ibanRegexThroughCountryCode = {
   IR: /^(IR[0-9]{2})\d{22}$/,
   IS: /^(IS[0-9]{2})\d{22}$/,
   IT: /^(IT[0-9]{2})[A-Z]{1}\d{10}[A-Z0-9]{12}$/,
-  JO: /^(JO[0-9]{2})[A-Z]{4}\d{22}$/,
+  JO: /^(JO[0-9]{2})[A-Z]{4}\d{4}[A-Z0-9]{18}$/,
   KW: /^(KW[0-9]{2})[A-Z]{4}[A-Z0-9]{22}$/,
   KZ: /^(KZ[0-9]{2})\d{3}[A-Z0-9]{13}$/,
   LB: /^(LB[0-9]{2})\d{4}[A-Z0-9]{20}$/,
diff --git a/test/validators.test.js b/test/validators.test.js
index 98d2a12ff..dab9786c2 100644
--- a/test/validators.test.js
+++ b/test/validators.test.js
@@ -6237,6 +6237,9 @@ describe('Validators', () => {
         'PS92PALS000000000400123456702',
         'PS92PALS00000000040012345670O',
         'IR576406610070915600106898',
+        'BY13NBRB3600900000002Z00AB00',
+        'AZ50NABZ0000000013701000194A',
+        'JO90CBJO001000000000013100030A',
       ],
       invalid: [
         'XX22YYY1234567890123',
@@ -6247,6 +6250,7 @@ describe('Validators', () => {
         'VG46H07Y0223060094359858',
         'IE95TE8270900834048660',
         'PS072435171802145240705922007',
+        'BY13NBRB36009000000020000000',
       ],
     });
     test({